kernel/linux.git/lib/Kconfig.kasan, branch v6.19.11

kasan: introduce ARCH_DEFER_KASAN and unify static key across modes

2025-09-21T21:21:58+00:00

Patch series "kasan: unify kasan_enabled() and remove arch-specific implementations", v6. This patch series addresses the fragmentation in KASAN initialization across architectures by introducing a unified approach that eliminates duplicate static keys and arch-specific kasan_arch_is_ready() implementations. The core issue is that different architectures have inconsistent approaches to KASAN readiness tracking: - PowerPC, LoongArch, and UML arch, each implement own kasan_arch_is_ready() - Only HW_TAGS mode had a unified static key (kasan_flag_enabled) - Generic and SW_TAGS modes relied on arch-specific solutions or always-on behavior This patch (of 2): Introduce CONFIG_ARCH_DEFER_KASAN to identify architectures [1] that need to defer KASAN initialization until shadow memory is properly set up, and unify the static key infrastructure across all KASAN modes. [1] PowerPC, UML, LoongArch selects ARCH_DEFER_KASAN. The core issue is that different architectures haveinconsistent approaches to KASAN readiness tracking: - PowerPC, LoongArch, and UML arch, each implement own kasan_arch_is_ready() - Only HW_TAGS mode had a unified static key (kasan_flag_enabled) - Generic and SW_TAGS modes relied on arch-specific solutions or always-on behavior This patch addresses the fragmentation in KASAN initialization across architectures by introducing a unified approach that eliminates duplicate static keys and arch-specific kasan_arch_is_ready() implementations. Let's replace kasan_arch_is_ready() with existing kasan_enabled() check, which examines the static key being enabled if arch selects ARCH_DEFER_KASAN or has HW_TAGS mode support. For other arch, kasan_enabled() checks the enablement during compile time. Now KASAN users can use a single kasan_enabled() check everywhere. Link: https://lkml.kernel.org/r/20250810125746.1105476-1-snovitoll@gmail.com Link: https://lkml.kernel.org/r/20250810125746.1105476-2-snovitoll@gmail.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217049 Signed-off-by: Sabyrzhan Tasbolatov Reviewed-by: Christophe Leroy Reviewed-by: Ritesh Harjani (IBM) #powerpc Cc: Alexander Gordeev Cc: Alexander Potapenko Cc: Alexandre Ghiti Cc: Alexandre Ghiti Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Baoquan He Cc: David Gow Cc: Dmitriy Vyukov Cc: Heiko Carstens Cc: Huacai Chen Cc: Marco Elver Cc: Qing Zhang Cc: Sabyrzhan Tasbolatov Cc: Vincenzo Frascino Signed-off-by: Andrew Morton

kasan: delete CONFIG_KASAN_MODULE_TEST

2024-11-11T08:26:44+00:00

Since we've migrated all tests to the KUnit framework, we can delete CONFIG_KASAN_MODULE_TEST and mentioning of it in the documentation as well. I've used the online translator to modify the non-English documentation. [snovitoll@gmail.com: fix indentation in translation] Link: https://lkml.kernel.org/r/20241020042813.3223449-1-snovitoll@gmail.com Link: https://lkml.kernel.org/r/20241016131802.3115788-4-snovitoll@gmail.com Signed-off-by: Sabyrzhan Tasbolatov Reviewed-by: Andrey Konovalov Cc: Alexander Potapenko Cc: Alex Shi Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Hu Haowen <2023002089@link.tyut.edu.cn> Cc: Jonathan Corbet Cc: Marco Elver Cc: Vincenzo Frascino Cc: Yanteng Si Signed-off-by: Andrew Morton

Revert "kasan: Disable Software Tag-Based KASAN with GCC"

2024-10-23T15:04:30+00:00

This reverts commit 7aed6a2c51ffc97a126e0ea0c270fab7af97ae18. Now that __no_sanitize_address attribute is fixed for KASAN_SW_TAGS with GCC, allow re-enabling KASAN_SW_TAGS with GCC. Cc: Andrey Konovalov Cc: Andrew Pinski Cc: Mark Rutland Cc: Will Deacon Signed-off-by: Marco Elver Reviewed-by: Andrey Konovalov Link: https://lore.kernel.org/r/20241021120013.3209481-2-elver@google.com Signed-off-by: Will Deacon

kasan: Disable Software Tag-Based KASAN with GCC

2024-10-15T10:38:10+00:00

Syzbot reports a KASAN failure early during boot on arm64 when building with GCC 12.2.0 and using the Software Tag-Based KASAN mode: | BUG: KASAN: invalid-access in smp_build_mpidr_hash arch/arm64/kernel/setup.c:133 [inline] | BUG: KASAN: invalid-access in setup_arch+0x984/0xd60 arch/arm64/kernel/setup.c:356 | Write of size 4 at addr 03ff800086867e00 by task swapper/0 | Pointer tag: [03], memory tag: [fe] Initial triage indicates that the report is a false positive and a thorough investigation of the crash by Mark Rutland revealed the root cause to be a bug in GCC: > When GCC is passed `-fsanitize=hwaddress` or > `-fsanitize=kernel-hwaddress` it ignores > `__attribute__((no_sanitize_address))`, and instruments functions > we require are not instrumented. > > [...] > > All versions [of GCC] I tried were broken, from 11.3.0 to 14.2.0 > inclusive. > > I think we have to disable KASAN_SW_TAGS with GCC until this is > fixed Disable Software Tag-Based KASAN when building with GCC by making CC_HAS_KASAN_SW_TAGS depend on !CC_IS_GCC. Cc: Andrey Konovalov Suggested-by: Mark Rutland Reported-by: syzbot+908886656a02769af987@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000f362e80620e27859@google.com Link: https://lore.kernel.org/r/ZvFGwKfoC4yVjN_X@J2N7QTR9R3 Link: https://bugzilla.kernel.org/show_bug.cgi?id=218854 Reviewed-by: Andrey Konovalov Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20241014161100.18034-1-will@kernel.org Signed-off-by: Will Deacon

treewide: update LLVM Bugzilla links

2024-02-22T23:38:51+00:00

LLVM moved their issue tracker from their own Bugzilla instance to GitHub issues. While all of the links are still valid, they may not necessarily show the most up to date information around the issues, as all updates will occur on GitHub, not Bugzilla. Another complication is that the Bugzilla issue number is not always the same as the GitHub issue number. Thankfully, LLVM maintains this mapping through two shortlinks: https://llvm.org/bz -> https://bugs.llvm.org/show_bug.cgi?id= https://llvm.org/pr -> https://github.com/llvm/llvm-project/issues/ Switch all "https://bugs.llvm.org/show_bug.cgi?id=" links to the "https://llvm.org/pr" shortlink so that the links show the most up to date information. Each migrated issue links back to the Bugzilla entry, so there should be no loss of fidelity of information here. Link: https://lkml.kernel.org/r/20240109-update-llvm-links-v1-3-eb09b59db071@kernel.org Signed-off-by: Nathan Chancellor Reviewed-by: Kees Cook Acked-by: Fangrui Song Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Daniel Borkmann Cc: Mykola Lysenko Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-01-09T19:18:47+00:00

Pull MM updates from Andrew Morton: "Many singleton patches against the MM code. The patch series which are included in this merge do the following: - Peng Zhang has done some mapletree maintainance work in the series 'maple_tree: add mt_free_one() and mt_attr() helpers' 'Some cleanups of maple tree' - In the series 'mm: use memmap_on_memory semantics for dax/kmem' Vishal Verma has altered the interworking between memory-hotplug and dax/kmem so that newly added 'device memory' can more easily have its memmap placed within that newly added memory. - Matthew Wilcox continues folio-related work (including a few fixes) in the patch series 'Add folio_zero_tail() and folio_fill_tail()' 'Make folio_start_writeback return void' 'Fix fault handler's handling of poisoned tail pages' 'Convert aops->error_remove_page to ->error_remove_folio' 'Finish two folio conversions' 'More swap folio conversions' - Kefeng Wang has also contributed folio-related work in the series 'mm: cleanup and use more folio in page fault' - Jim Cromie has improved the kmemleak reporting output in the series 'tweak kmemleak report format'. - In the series 'stackdepot: allow evicting stack traces' Andrey Konovalov to permits clients (in this case KASAN) to cause eviction of no longer needed stack traces. - Charan Teja Kalla has fixed some accounting issues in the page allocator's atomic reserve calculations in the series 'mm: page_alloc: fixes for high atomic reserve caluculations'. - Dmitry Rokosov has added to the samples/ dorectory some sample code for a userspace memcg event listener application. See the series 'samples: introduce cgroup events listeners'. - Some mapletree maintanance work from Liam Howlett in the series 'maple_tree: iterator state changes'. - Nhat Pham has improved zswap's approach to writeback in the series 'workload-specific and memory pressure-driven zswap writeback'. - DAMON/DAMOS feature and maintenance work from SeongJae Park in the series 'mm/damon: let users feed and tame/auto-tune DAMOS' 'selftests/damon: add Python-written DAMON functionality tests' 'mm/damon: misc updates for 6.8' - Yosry Ahmed has improved memcg's stats flushing in the series 'mm: memcg: subtree stats flushing and thresholds'. - In the series 'Multi-size THP for anonymous memory' Ryan Roberts has added a runtime opt-in feature to transparent hugepages which improves performance by allocating larger chunks of memory during anonymous page faults. - Matthew Wilcox has also contributed some cleanup and maintenance work against eh buffer_head code int he series 'More buffer_head cleanups'. - Suren Baghdasaryan has done work on Andrea Arcangeli's series 'userfaultfd move option'. UFFDIO_MOVE permits userspace heap compaction algorithms to move userspace's pages around rather than UFFDIO_COPY'a alloc/copy/free. - Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm: Add ksm advisor'. This is a governor which tunes KSM's scanning aggressiveness in response to userspace's current needs. - Chengming Zhou has optimized zswap's temporary working memory use in the series 'mm/zswap: dstmem reuse optimizations and cleanups'. - Matthew Wilcox has performed some maintenance work on the writeback code, both code and within filesystems. The series is 'Clean up the writeback paths'. - Andrey Konovalov has optimized KASAN's handling of alloc and free stack traces for secondary-level allocators, in the series 'kasan: save mempool stack traces'. - Andrey also performed some KASAN maintenance work in the series 'kasan: assorted clean-ups'. - David Hildenbrand has gone to town on the rmap code. Cleanups, more pte batching, folio conversions and more. See the series 'mm/rmap: interface overhaul'. - Kinsey Ho has contributed some maintenance work on the MGLRU code in the series 'mm/mglru: Kconfig cleanup'. - Matthew Wilcox has contributed lruvec page accounting code cleanups in the series 'Remove some lruvec page accounting functions'" * tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits) mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER mm, treewide: introduce NR_PAGE_ORDERS selftests/mm: add separate UFFDIO_MOVE test for PMD splitting selftests/mm: skip test if application doesn't has root privileges selftests/mm: conform test to TAP format output selftests: mm: hugepage-mmap: conform to TAP format output selftests/mm: gup_test: conform test to TAP format output mm/selftests: hugepage-mremap: conform test to TAP format output mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large mm/memcontrol: remove __mod_lruvec_page_state() mm/khugepaged: use a folio more in collapse_file() slub: use a folio in __kmalloc_large_node slub: use folio APIs in free_large_kmalloc() slub: use alloc_pages_node() in alloc_slab_page() mm: remove inc/dec lruvec page state functions mm: ratelimit stat flush from workingset shrinker kasan: stop leaking stack trace handles mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE mm/mglru: add dummy pmd_dirty() ...

kasan: record and report more information

2023-12-11T00:51:55+00:00

Record and report more information to help us find the cause of the bug and to help us correlate the error with other system events. This patch adds recording and showing CPU number and timestamp at allocation and free (controlled by CONFIG_KASAN_EXTRA_INFO). The timestamps in the report use the same format and source as printk. Error occurrence timestamp is already implicit in the printk log, and CPU number is already shown by dump_stack_lvl, so there is no need to add it. In order to record CPU number and timestamp at allocation and free, corresponding members need to be added to the relevant data structures, which will lead to increased memory consumption. In Generic KASAN, members are added to struct kasan_track. Since in most cases, alloc meta is stored in the redzone and free meta is stored in the object or the redzone, memory consumption will not increase much. In SW_TAGS KASAN and HW_TAGS KASAN, members are added to struct kasan_stack_ring_entry. Memory consumption increases as the size of struct kasan_stack_ring_entry increases (this part of the memory is allocated by memblock), but since this is configurable, it is up to the user to choose. Link: https://lkml.kernel.org/r/VI1P193MB0752BD991325D10E4AB1913599BDA@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM Signed-off-by: Juntong Deng Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Vincenzo Frascino Signed-off-by: Andrew Morton

kasan: default to inline instrumentation

2023-12-11T00:51:40+00:00

KASan inline instrumentation can yield up to a 2x performance gain at the cost of a larger binary. Make inline instrumentation the default, as suggested in the bug report below. When an architecture does not support inline instrumentation, it should set ARCH_DISABLE_KASAN_INLINE, as done by PowerPC, for instance. Link: https://lkml.kernel.org/r/20231109155101.186028-1-paul.heidekrueger@tum.de Signed-off-by: Paul Heidekrüger Reported-by: Andrey Konovalov Reviewed-by: Marco Elver Closes: https://bugzilla.kernel.org/show_bug.cgi?id=203495 Acked-by: Andrey Konovalov Cc: Dmitry Vyukov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Vincenzo Frascino Signed-off-by: Andrew Morton

mm/slab: remove CONFIG_SLAB from all Kconfig and Makefile

2023-12-05T10:14:40+00:00

Remove CONFIG_SLAB, CONFIG_DEBUG_SLAB, CONFIG_SLAB_DEPRECATED and everything in Kconfig files and mm/Makefile that depends on those. Since SLUB is the only remaining allocator, remove the allocator choice, make CONFIG_SLUB a "def_bool y" for now and remove all explicit dependencies on SLUB or SLAB as it's now always enabled. Make every option's verbose name and description refer to "the slab allocator" without refering to the specific implementation. Do not rename the CONFIG_ option names yet. Everything under #ifdef CONFIG_SLAB, and mm/slab.c is now dead code, all code under #ifdef CONFIG_SLUB is now always compiled. Reviewed-by: Kees Cook Reviewed-by: Christoph Lameter Acked-by: David Rientjes Tested-by: David Rientjes Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka

kasan: treat meminstrinsic as builtins in uninstrumented files

2023-03-03T05:54:22+00:00

Where the compiler instruments meminstrinsics by generating calls to __asan/__hwasan_ prefixed functions, let the compiler consider memintrinsics as builtin again. To do so, never override memset/memmove/memcpy if the compiler does the correct instrumentation - even on !GENERIC_ENTRY architectures. [elver@google.com: powerpc: don't rename memintrinsics if compiler adds prefixes] Link: https://lore.kernel.org/all/20230224085942.1791837-1-elver@google.com/ [1] Link: https://lkml.kernel.org/r/20230227094726.3833247-1-elver@google.com Link: https://lkml.kernel.org/r/20230224085942.1791837-2-elver@google.com Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions") Signed-off-by: Marco Elver Reviewed-by: Andrey Konovalov Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Acked-by: Michael Ellerman (powerpc) Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Borislav Petkov (AMD) Cc: Dave Hansen Cc: Dmitry Vyukov Cc: Ingo Molnar Cc: Jakub Jelinek Cc: Kees Cook Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Nicolas Schier Cc: Peter Zijlstra (Intel) Cc: Thomas Gleixner Cc: Vincenzo Frascino Signed-off-by: Andrew Morton